检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2024年第2期66卷 110-118页

作者： Sheng Wan Rong Xie Jianhong Fan kewen tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China

Gold(Au)and palladium(Pd)play an increasing role in the production and human life;Therefore,it is of great significance to study their recovery.A 5,11,17,23-tetra-ethylthio-25,26,27,28-tetra-hydroxyl thiacalix[4]arene(TCAET)was synthesized specifically for the capture of Au(Ⅲ)and Pd(Ⅱ)from HCl medium by liquid-liquid *** a 0.1 mol·L^(-1)HCl medium,the transfer of Au(Ⅲ)and Pd(Ⅱ)from the aqueous phase to the organic phase was highly efficient,with a transfer ratio of 100%for Au(Ⅲ)and 98%for Pd(Ⅱ).Furthermore,the extraction equilibrium time for Au(Ⅲ)was just 5 ***'s method data demonstrated that TCAET formed complexes with Au(Ⅲ)and Pd(Ⅱ)in a ratio of 2:3 and 1:1,respectively,during the extraction *** showed high selectivity toward Pd(Ⅱ)and Au(Ⅲ)over other competing metal ***,both Au(Ⅲ)and Pd(Ⅱ)could be successfully stripped from the loaded organic phases with a 1.0 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl and 0.5 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl,*** obtained from five consecutive extraction-stripping cycles showed good reusability of TCAET toward Au(Ⅲ)and Pd(Ⅱ)*** conclusion can provide a certain reference for thiacalixarene in the recovery of precious metal species.

关键词： Thiacalixarene Upper-rim modification Liquid-liquid extraction Precious metal Thioether

Enantioselective esterification of(R,S)-2-(4-methylphenyl)propionic acid via Novozym 435:Optimization and application

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第7期28卷 1816-1823页

作者： Xin Yuan LujunWang Panliang Zhang Weifeng Xu kewen tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China

This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic *** 435(CALB)has the best catalytic performance compared with other *** the alcohols screened,n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in *** surface methodology(RSM)was used to evaluate the influence of the factors,such as temperature,enzyme amount,substrate concentration and reaction time on the substrate conversion(c)and enantiomeric excess(ee).The correlation coefficient R2 for enantiomeric excess and the conversion are 0.9827 and 0.9910,respectively,indicating that can accurately predict the experimental *** simulation and optimization,the optimal conditions were obtained,involving 600 mmol·L^-1 MPPA concentration(0.60 mmol),850 mmol·L^-1 hexanol concentration(0.85 mmol),58 mg enzyme amount,75℃temperature and 4.5 h reaction time,*** the optimized conditions,the experimental values of conversion and enantiomeric excess were 89.34%and 97.84%,respectively,which are in good agreement with the model predictions.

关键词： (R,S)-2-(4-Methylphenyl)propionic acid Novozym 435 Esterification kinetic resolution Response surface methodology

Kinetic study on reactive extraction for chiral separation of phenylsuccinic acid enantiomers

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第11期53卷 2399-2406页

作者： tang kewen MIAO JiaBing ZHOU Tao SONG LiTao Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China

The kinetics of the extraction of phenylsuccinic acid(PSA) enantiomers by hydroxypropyl-β-cyclodextrin(HP-β-CD) in a modified Lewis cell was studied,in which HP-β-CD dissolved in 0.1 mol L-1 NaH2PO4/H3PO4 buffer solution(pH = 2.5) was selected as the chiral *** enantiomers were extracted from organic phase to aqueous phase in the extraction *** theory of extraction accompanied by a chemical reaction has been used to obtain the intrinsic kinetics of this extraction *** different parameters affecting the extraction rate such as agitation speed,interfacial area,initial concentration of PSA enantiomers in organic phase as well as HP-β-CD concentration in aqueous phase were separately *** experimental results demonstrate that the extraction reactions are *** reactions were found to be first order with respect to PSA and second order with respect to HP-β-CD with forward rate constants of 3.4 × 10-2 m6 mol-2 s-1 for R-PSA and 9.96 × 10?3 m6 mol-2 s-1 for *** data will be useful in the design of extraction processes.

关键词： kinetics reactive extraction chiral separation Lewis cell phenylsuccinic acid enantiomers

Modeling multiple chemical equilibrium for reactive extraction of naproxen enantiomers with HP-β-CD as hydrophilic selector

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2011年第7期54卷 1130-1137页

作者： tang kewen ZHANG PanLiang PAN ChunYue LI HongJian Department of Chemistry and Chemical Engineering Hunan Institute of Science and Technology Yueyang 414006 China College of Chemistry and Chemical Engineering Central South University Changsha 410083 China

Reactive extraction is an emerging technology for large-scale continuous resolution of drug enantiomers. The enantioselective extraction of R,S-naproxen by hydrophilic HP-β-CD in 1,2-dichloroethane was studied at 5℃. The experimental data were described by a reactive extraction model with a homogeneous aqueous phase reaction of R,S-naproxen with HP-β-CD which couples a complete description of chemical equilibria in aqueous phase with the overall phase equilibria of the system. Important parameters of this model were determined experimentally. The physical distribution coefficients for molecular and ionic NAP were 0.041 and 1.730, respectively. Here we show that the efficiency of extraction depends strongly on two process variables including pH and HP-β-CD concentration. The model predictions are compared graphically with the results of pre- vious experiments and there is a good agreement between each other. By the use of modeling and experiment, an optimized extraction condition with pH of 2.5 and HP-β-CD concentration of 0.1 mol/L was obtained with high enantioselectivity （a） of 1.59 and performance factor （pf） of 0,049. The model gives a good means of predicting enantiomers partitioning over a range of experimental conditions.

关键词： reactive extraction chiral separation naproxen enantiomers modelling hydroxypropyl-βcyclodextrin

Equilibrium of liquid-liquid extraction of 2-phenylbutyric acid enantiomers: Experiment and model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第4期26卷 708-714页

作者： Weifeng Xu Guilin Dai kewen tang Panliang Zhang Biquan Xiong Yu Liu Department of Chemistry and Chemical Engineering Hunan Institute of Science and Technology

The utilization of liquid–liquid extraction for the separation of 2-phenylbutyric acid（2-PBA） enantiomers was proposed. Factors affecting the extract process were investigated, including organic solvents, β-cyclodextrin derivatives, cyclodextrin concentration, p H and temperature. A model was proposed to describe the separation process based on the homogeneous phase reaction mechanism. Important parameters of this model were determined experimentally. The physical distribution coefficients for molecular and ionic 2-PBA were0.129 and 7.455, respectively. The equilibrium constants of the complexation reactions were 89.36 and36.78 L·mol^-1 for（＋）-and（-）-2-PBA, respectively. The model was verified by experiments and proved to be an excellent means to optimize the separation system. Through modeling prediction and experiment, the best conditions（e.g., pH value of 3.00, extractant concentration of 0.1 mol·L^-1, temperature of 5.0 ℃） were acquired. Under this condition, the maximum enantioselectivity（2.096） was obtained.

关键词： Model Simulation Enantioselective extraction 2-Phenylbutyric acid Hydrophilic selector

Study on extraction kinetics ofα-cyclopentylmandelic acid enantiomers with hydroxyethyl-β-cyclodextrin as chiral selector

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第1期26卷 67-72页

作者： Panliang Zhang Pan Jiang Weifeng Xu Yu Liu Biquan Xiong Yunren Qiu kewen tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China College of Chemical Engineering Xiangtan UniversityXiangtan 411105China

In this work,the kinetic study on reactive extraction ofα-cyclopentylmandelic acid(α-CPMA)enantiomers was performed in a Lewis cell using hydroxyethyl-β-cyclodextrin(HE-β-CD)as chiral *** enantioselective complexation equilibrium between HE-β-CD andα-CPMA enantiomers was studied by phase solubility *** important process parameters affecting the initial extraction rate were separately studied and the reaction rate equations were *** optimal conditions for kinetic study were as follows:stirring speed of 75 r·min^(-1),interfacial area of 12.56 cm^2,pH of 2.5,initial HE-β-CD concentration of 0.05 mol·L^(-1),initialα-CPMA concentration of 5 mmol·L^(-1),and temperature of 278 *** reaction has been found to be first order inα-CPMA and second order in HE-β-CD with the forward rate constants of 2.056×10^(-3)m^6·mol^(-2)·s^(-1)and 1.459×10^(-3)m^6·mol^(-2)·s^(-1)for(S)-α-CPMA and(R)-α-CPMA,*** complexation equilibrium constants were evaluated as 61 L·mol^(-1) and 117 L·mol^(-1)for(S)-α-CPMA and(R)-α-CPMA,and the intrinsic enantioselectivity is estimated as 1.92.

关键词： Kinetics Liquid-liquid extraction Chiral resolution α-Cyclopentylmandelic acid

多级离心逆流萃取萘普生对映体模拟及实验研究

在线全文

学校读者我要写书评

暂无评论

化工学报 2013年第11期64卷 4074-4081页

作者：唐课文文平张盼良黄燕湖南理工学院化学化工学院湖南岳阳414006 湘潭大学化工学院湖南湘潭411105

基于萘普生(NAP)对映体的单级手性萃取数学模型和质量守恒定律,建立了多级离心逆流萃取萘普生对映体数学模型。采用Matlab语言编写程序模拟了相比、萃取剂浓度、水相pH值等参数对萃取相出口对映体过剩量和产率的影响,并经实验研究对模... 详细信息

基于萘普生(NAP)对映体的单级手性萃取数学模型和质量守恒定律,建立了多级离心逆流萃取萘普生对映体数学模型。采用Matlab语言编写程序模拟了相比、萃取剂浓度、水相pH值等参数对萃取相出口对映体过剩量和产率的影响,并经实验研究对模型模拟进行验证。结果表明:采用中间进料,对映体浓度[R,SNAP]=0.025mol·L-1、萃取剂浓度[C]=0.050mol·L-1、相比W/O=7、水相pH=2.5、温度T=5℃时,经10级离心逆流萃取后萃取相出口S-NAP对映体过剩量为45%,相应的产率60%,实验结果和模型模拟值符合得很好。

关键词：萘普生计算机模拟萃取离心分离器模型

基于MALDI-TOF MS质谱峰分析细菌耐药性的研究进展

在线全文

学校读者我要写书评

暂无评论

中华微生物学和免疫学杂志 2021年第3期41卷 242-248页

作者：唐克文李从荣汪倩钰汤冬玲武汉大学人民医院检验科 430060

基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)已成为微生物鉴定领域广泛应用的方法,其快速、准确、高通量等明显优势吸引众多研究探索其他微生物领域适用范围,当前已报道了多个基于MALDI-TOF MS对细菌进行耐药分析的研究,通过对质... 详细信息

基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)已成为微生物鉴定领域广泛应用的方法,其快速、准确、高通量等明显优势吸引众多研究探索其他微生物领域适用范围,当前已报道了多个基于MALDI-TOF MS对细菌进行耐药分析的研究,通过对质谱进行简单的视觉分析或利用信息学和统计学对整个质谱进行更复杂的分析来识别耐药相关的特异质谱峰,因此MALDI-TOF MS成为检测抗生素耐药性的潜在工具,本综述主要阐述了利用MALDI-TOF MS检测细菌耐药性的研究进展。

关键词：基质辅助激光解吸电离飞行时间质谱耐药性细菌

Equilibrium Studies on Liquid-Liquid Reactive Extraction of Phenylsuccinic Acid Enantiomers Using Hydrophilicβ-CD Derivatives Extractants

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2011年第3期19卷 397-403页

作者：唐课文苗家兵周涛刘永兵 Department of Chemistry and Chemical Engineering Hunan Institute of Science and Technology College of Chemistry and Chemical Engineering Central South University

This paper deals with the enantioseparation of phenylsuccinic acid(H2A)enantiomers by liquid-liquid reactive extraction usingβ-CD derivatives as aqueous *** and its derivatives can interact with guest molecules selectively to form complexes with different *** derivatives are not soluble in organic liquids,but highly soluble in *** this work,hydroxypropyl-β-cyclodextrin(HP-β-CD),hydroxyethyl- β-cyclodextrin(HE-β-CD)and methyl-β-cyclodextrin(Me-β-CD)were selected as chiral selectors in aqueous phase for the reactive extraction of phenylsuccinic acid enantiomers from organic phase to aqueous *** results show that the efficiency of the extraction depends,often strongly,on a number of process variables,including the types of organic solvents andβ-CD derivatives,the concentrations of the extractants and H2A enantiomers,pH and ***-β-CD,HE-β-CD and Me-β-CD have stronger recognition abilities for R-phenylsuccinic acid than for S-phenylsuccinic *** the three kinds ofβ-CD derivatives,HP-β-CD has the strongest separation ability. Excellent enantioseparation was achieved under the optimal conditions of pH of 2.5 and temperature of 5°C with a maximum enantioselectivity(a)of *** extraction of enantiomers with hydrophilicβ-CD derivatives is of strong chiral separation ability and can be hopeful for separations of various enantiomers at a large-scale.

关键词： solvent extraction enantiomer resolution β-CD derivatives phenylsuccinic acid enantiomers

在线全文

学校读者我要写书评

暂无评论

海泡石原位晶化合成NaY分子筛的研究

化学学报 2010年第4期68卷 329-333页

作者：郑淑琴韩勇黄石钱东唐课文易健民湖南理工学院化学化工系岳阳414000 中南大学化学化工学院长沙410083

首次用海泡石为硅源、高岭土为铝源,在水热条件下原位晶化合成NaY分子筛,采用粉末X射线衍射仪、电子扫描电镜等测试手段对所合成样品进行表征分析,着重考察晶化温度和投料配比对产品相对结晶度的影响.研究结果表明,NaY分子筛的形成受晶... 详细信息

首次用海泡石为硅源、高岭土为铝源,在水热条件下原位晶化合成NaY分子筛,采用粉末X射线衍射仪、电子扫描电镜等测试手段对所合成样品进行表征分析,着重考察晶化温度和投料配比对产品相对结晶度的影响.研究结果表明,NaY分子筛的形成受晶化温度的影响最大,随温度的升高,产品的相对结晶度显著提高,晶化温度升至100℃时,得到结晶度较高的NaY分子筛晶体.在原位晶化体系中,随n(SiO2)/n(Al2O3)减小,其相对结晶度增大;增加体系的n(Na2O)/n(SiO2)和减小n(H2O)/n(Na2O)都增大产品的相对结晶度;n(SiO2)/n(Al2O3)在投料比影响因素中占主导地位.

关键词：海泡石 NaY 原位晶化合成